Papermaking machine forming member



Dec. 22, 1964 H. H. HELLER PAPERMAKING MACHINE FORMING MEMBER Filed May 18. 1961 2 Sheets-Sheet 1 H. H. HELLER PAPERMAKING momma FORMING MEMBER Dec. 22, 1964 2 Sheets-Sheet 2 Filed May 18. 1961 United States Patent 3,162,567 YAPERhIAKlNG MACHINE FORD ENG hiEMBER Harold H. Heller, Appleton, Wis, assignor to Kimberly- Clark tlorporation, Neenah, Wis a corporation of Delaware Filed May 18, 1961, Ser. No. 110,932 3 Claims. (Cl. 162-648) My invention relates to pap'ermaking' machines, particularly of the Fourdrinier type; and the invention relates more particularly to improved Fourdrinier web forming belts for such machines.

The web forming belts in Fourdrinier papermaking machines function to drain water from the stock applied onto them by virtue of the drainage openings through the belt. These belts are generally fabrics woven with warp strands extending in one direction, particularly in the machine direction (which is that direction in which the fabric is moved as stock is applied onto it), interwoven with shute strands extending in the other direction. The weaving process is necessarily quite time consuming and expensive due to the fact that each of the shute strands must pass between various ones of the warp strands and each shute strand must thus be put into place individually.

It is an object of the present invention to provide an improved web forming belt, particularly for Fourdrinier machines, which is very much simpler in construction and is, therefore, considerably cheaper to manufacture, than the conventional woven fabrics.

More particularly, it is an object of the present invention to provide an improved Fourdrinier web forming belt which is made from a sheet of metal or other suitable material that is simply punched in order to provide water drainage openings for the stock applied on the belt.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed, for carrying out the above stated objects and such other objects, as will be apparent from the following description of preferred forms of the invention, illustrated with reference to the accompanying drawings, wherein:

FIG. 1 is a side view, partially schematic, of a Fourdrinier web forming machine including a web forming belt movably trained in the form of a loop about a plurality of supporting rolls and including a stock inlet for applying stock onto the belt;

FIG. 2 is a perspective plan view of the forming belt used in the web forming machine;

FIG. 3 is a perspective plan view of another embodiment of the forming belt;

FIG. 4 is a side View of a pair of embossing rolls for forming a web forming belt of the invention; and

FIG. 5 is a perspective view of a forming mold for a belt of the invention which is made of a flexible plastic.

Like characters of reference designate like parts in the several views.

Referring now to the drawings, and in particular to FIG. 1, the illustrated paperrnaking machine may be seen to comprise a foraminous, endless, web forming belt movably positioned about a breast roll 13, a couch roll 12, table rolls 13 and a guide roll 14. A vacuum box 15 is positioned beneath the belt 10 and in contact with it.

Referring now to FIG. 2, it will be observed that the belt 10 is formed of a single length of sheet material 50. This may be, for example, a sheet of metal and, in particular, a rolled sheet of a ductile metal such as bronze, brass, Monel or other copper alloys which can well withstand the cold working to which the sheet is subjected due to its travel about the rolls 11, i2, 13 and 14. Alter- 3,152,567 Patented Dec. 22, 1964 nately, the material of the belt 10 may be a suitable flexible plastic.

The sheet material of the belt 10 is provided with a plurality of arches 51 which have been formed upwardly out of the plane of the sheet so as to provide sidewardly extending drainage openings 52 beneath the arches. The side of the belt 10 illustrated in FIG. 2 may be the papermakin'g side of the belt so that the paper stock fibers drape over the arches and water from the stock drains sidewardly beneath the arches through the openings 52. The belt 10 shall preferably move in the direction indicated by the arrow A with the arches 51 and openings 52 being transverse to the direction of movement to the belt. In view of the fact that the openings 52 are elongated in the transverse direction, the stock fibers which are deposited on the belt 10 as it moves in the machine direction A and more of which, therefore, initially extend in the machine direction A than in the transverse direction, are turned tosorne extent by the white water as it drains through the transversely extending openings 52 to provide a web that has an extraordinary number of fibers extending transversely and which is, therefore, strengthened in the transverse direction.

The lengths of the fibers in paperm'aking stock generally are between .008 inch and .20 inch. With these measurements as the basis, a suggested height and width of each of the arches could be .008 inch and .010 inch, respectively; adjacent rows of the arches could be spaced .010 inch apart; and the arches may be formed in the belt so as to provide openings 52 of .025 inch in length, all as indicated in FIG. 2. It will be understood that the above measurements are given only for the purpose of illustration and that these dimensions can well be varied.

These dimensions of the openings 52 may be compared with the sizes of the openings in some paperrnaking fabrics made up of interwoven warp and shute wires that are in common use. The warp and shute strands in such fabrics may have a diameter of from .010 inch to .015 inch, for example, and the widest space between strands may be from .025 inch between adjacent warp strands to about .015 inch between adjacent shute strands. Thus, the rectangular openings provided by adjacent warp and shute strands may have projected dimensions on a plane parallel to that of the fabric of about .015 inch x .025 inch. These dimensions are for paperrnaking wires of relatively coarse texture and, of course, the finer fabrics have dimensions considerably less.

Papermaking fibers, in order to be retained on a Web forming belt, should be considerably longer than the longest opening in the belt, such as about 8 times as long as a satisfactory average. Using this as a criterion, the length of the openings 52 should preferably be no more than .025 inch, and may be less, in order to provide satisfactory fiber retention.

The arches 51 may, for example, be embossed and punched in the belt 10 such as by running the metal sheet 50 of the belt between a pair of embossing rolls 53 and 54. The rolls 53 and 54 may be provided with mating projections and depressions corresponding to the shapes of the arches 51 so that these arches are punched in the metal sheet 50 as it passes between the rolls 53 and 54.

It will be noted that the plane of each of the openings 52 is at right angles to the plane of the metal sheet 50. This direction of extent of the opening planes corresponds to some extent to those of the drainage openings in woven Fourdrinier wires of types now commonly used. The latter have openings of a variety of shapes and some are so oriented that the water flows through the fabric in directions not exactly perpendicular to the general plane of the fabric.

Although the material of the belt 10 is preferably metal, the belt 10 may also be formed of a sheet of flexible plastic. Such a sheet may be formed to have the arches 51 by being cast on a metal forming mold 55 having arch shaped projections 56 on its upper surface. The belt could be so cast in a single length, and its ends could then be joined in order to form the completed belt. The resultant product is a plastic flexible sheeting which is dimensionally quite stable and in particular is not sleazy, such as a woven fabric of synthetic strands might be.

Although it is preferred that the belt may be used with its side illustrated in FIG. 2 as the papermaking side and travelling in the direction A, my invention contemplates that such a belt may be used with its underside as a papermaking side, in which case the arches 51 project inwardly of the endless belt 10 (that is, downwardly of the belt 10 on the upper run of the belt between the rolls 11 and 12) and travel in a contact with the rolls 11, 12, 13 and 14. Also, in either case, the arches 51, if desired, could be punched in the belt 10 to extend in the machine direction, such as in the direction B illustrated in FIG. 2.

Another, modified, form of web forming belt that may be used is illustrated in FIG. 3. In this embodiment, tongues or lips 57 having plane portions 58 have been punched in the belt so as to provide openings 59 whigh extend generally transversely of the machine direction of travel indicated by the arrow C and are approximately perpendicular to the plane of the sheet material of the belt. The rows of punched lips 57 may, as an example, be .010 inch apart; the height of the openings 59 may be .006 inch; the length of the lips 57 may be .020 inch and the width of the lips 57 may be .010 inch, all as indicated in FIG. 3. These dimensions correspond generally with the dimensions given for the arches 51 in the FIG. 2 form of the belt and can very well be less to provide a less coarse web forming belt.

The web forming belts, as above described, advantageously have drainage openings formed by the upraised arches or lips which are generally perpendicular to the plane of the belt. Drainage from the stock on the belts thus takes place generally at right angles to the plane of the'belt for good web formation. Also, using the belts illustrated in FIGS. 2 and 3 in the preferred manner, the longest dimensions of the openings 52 and 59 in the belts lie transverse to the machine direction, which is the direction in which stock is deposited on the belts by the inlet 16. The paper fibers thus tend to bend and turn; during formation, from the machine direction to the cross machine direction for increased web strength in the latter direction.

I Wish it to be understood that the invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be understood to those skilled in the art that changes may be made without departing from the principles of the invention.

I claim:

1. A perforate stock draining support for forming a web of a fluent mass of fibers and water. comprising a belt of flexible sheet material, said belt having arched portions thereof extending out of the plane of the sheet material so as to provide drainage openings beneath the arched portions which are at angles to the plane of the sheet material.

2. A perforate stock draining support for forming a web of a fluent mass of fibers and water comprising a belt of flexible sheet material, said belt having arched portions which are arranged in a uniform pattern and which are punched out of the plane of the sheet material and extend transversely across the belt so as to provide water drainage openings which are at angles to the plane of the sheet material and which also extend transversely of the belt.

3. A perforate paper stock'drainage support comprising an endless belt of flexible sheet material adapted to be mounted in the form of a loop on a plurality of spaced rotatable rolls and to have a fluent stock of paper fibers and water directed onto the outer surface of the loop for draining the stock to form a paper web on said outer surface, said belt having rectangular portions thereof which extend out of the plane of the belt and are disposed in'rows across the belt, said portion providing drainage openings in the belt which are at angles to the plane of the sheet material, said openings being between .020 inch and .025 inch in length and being about .006 inch to .008 inch in height, and said rows being spaced about .010 inch apart and said portions being about .010 inch in width.

References Cited in the file of this patent UNITED STATES PATENTS 1,616,222 Harrigan Feb. 1, 1927 1,925,917 Chalon Sept. 5, 1933 1,927,791 Balfe Sept. 19, 1933 2,032,923 Eldridge Mar. 3, 1936 2,234,342 Jordan Mar. 11, 1941 2,596,997 Harter May 20, 1952 2,992,681 Hornbostel et a1. July 18, 1961 FOREIGN PATENTS 16,478 Australia June 10, 1904 387,206 Germany Dec. 27,1923 871,689 Germany Mar. 26, 1953 

1. A PERFORATE STOCK DRAINING SUPPORT FOR FORMING A WEB OF A FLUENT MASS OF FIBERS AND WATER COMPRISING A BELT OF FLEXIBLE SHEET MATERIAL, SAID BELT HAVING ARCHED PORTIONS THEREOF EXTENDING OUT OF THE PLANE OF THE SHEET MATERIAL SO AS TO PROVIDE DRAINAGE OPENINGS BENEATH THE ARCHED PORTIONS WHICH ARE AT ANGLES TO THE PLANE OF THE SHEET MATERIAL. 